I introduced 20 Red Cherry Shrimp to my tank just after Xmas and up until this morning they had doubled in number at least, plus I had at least four heavily pregnant females, so all was well. At 09:00ish this morning I replaced a large Amazon Sword plant (heavy with algae) with a number of Ceratopteris sp. Water Sprite and Cabomba caroliniana cuttings AKA Green Cabomba from a supllier I trust and have used many times. All seemed to go well, so I turn off the light to the tank and went out. On my return at 14:00ish I turned the light back on and was greeted with what looks to be all of my shrimp dead or dying on the floor of the tank! I’ve tested the water for copper and all is clear, so could this simply be stress or do those plants cause a problem with shrimp? I’d really like to understand what has happened here as I’m afraid if I replace them I may be endangering the new shrimp.

I don’t think the change in plant types has anything to do with the loss of the shrimp, my immediate thought would be that something was introduced with the plants, possibly an insecticide of some sorts???

From past discussions I do know that the likes of the spot-on anti flea treatments we use for cat and dogs need to be well cleaned off hands before putting them in the tank (your hands that is!!) as a small carry over can kill off invertebrates. Had the plants been treated with anything prior to purchase??

Thanks for the reply! I’m not sure yet as I’m awaiting a response from the supplier, but as I’ve stated in my post, I’ve used this supplier many times, infact everytime I buy plants and I haven’t had a problem in the past.

A number of the shrimps are trying their hardest to get themselves going again, but just can’t, to me it seems like a chemical reaction. I have in the last few mins realised I put some silicone sealant in the water at the time of the plant change, but I’ve used it before with no problem, but maybe I haven’t waited long enough for it to dry? It is aquarium safe however.

…………………….I have in the last few mins realised I put some silicone sealant in the water at the time of the plant change, but I’ve used it before with no problem, but maybe I haven’t waited long enough for it to dry? It is aquarium safe however.………………….

Uhm……

How big is the tank and how much silicone did you use????

I’m sure you will find silicon sealant as it comes out the tube will release acetic acid (or at least something that smells very like it) as part of the curing process. Are shrimps prone to sudden shifts in pH???

I’m sure you will find silicon sealant as it comes out the tube will release acetic acid (or at least something that smells very like it) as part of the curing process. Are shrimps prone to sudden shifts in pH???

Andrew

It’s a 60L cube (my son’s tank) and I used very little silicon really, it was simly used to stick a piece of slate to some bogwood to make it more stable.

I’ve done a full set of tests this morning (results below) and everything seems normal.

Amonia = 0ppmNitrIte = 0ppmNitrAte = 0ppmPH Level = 7.8ppm

I really only have one or two females trying to move now, both heavily pregnant and both of them are jetting themselves around, but then just flowing to the floor and jetting off again…not good!

I’d be inclined to remove the surviving female and put her in fresh water – she might not survive but the eggs she is carrying may not have been affected if they haven’t hatched yet, same goes for the other female that was carrying eggs if you haven’t already dumped the body.

Off topic a bit maybe, but I’m curious about the toxicity of copper to crustaceans. Recently I treated a tank full of snails (but no fish) with my own patent snail killer (recipe below). This killed the snails stone dead – they didn’t recover as they would normally do using proprietary snail treatments, probably because my solution would have been a massive overdose (I never use this stuff in a tank with fish in).

What surprised me was that there was quite a number of Cyclops in the tank and these appeared to be completely unaffected. Two weeks later I put some cherry shrimps in the tank and they are still thriving. I can’t say that the shrimps are unaffected by copper as it may have disappeared from solution by the end of two weeks, but at least the survival of the copepods suggests that copper isn’t necessarily as terminal to all crustaceans as generally put about. I’m tempted to experiment further with this.

(Home made snail treatment, Copper acetate, made by connecting 2 bits of copper wire to a battery or other DC supply and immersing them in vinegar in a small spice jar. The vinegar turns a lovely blue colour as the wire connected to the + side of the battery rots away. Make sure the two bits of copper don’t touch each other.)

Just an update for the guys who give advice. I did move my one remaining pregnant shrimp and two Guppies to a clean tank for two days and cleaned down the other tank. Since returning the shrimp she has had what seem to be perfectly health babies and she is doing fine herself. Still not sure what caused it, but I’m now restocked with 40 shrimp and all is well…kind of!